package com.moon.interface_api.utils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;

import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

@Slf4j
public class JwtUtil {
    /**
     * 登录Token的生成和解析
     * 
     */

    /** token秘钥，请勿泄露，请勿随便修改 */
    public static final String SECRET = "chile";
    /** token 过期时间: 10天 */
    public static final int calendarField = Calendar.DATE;
    public static final int calendarInterval = 10;

    /**
     * JWT生成Token.<br/>
     * 
     * JWT构成: header, payload, signature
     * 
     * @param user_id
     * 登录成功后用户user_id, 参数user_id不可传空
     */
    public static String createToken(Long user_id) throws Exception {
        Date iatDate = new Date();
        // expire time
        Calendar nowTime = Calendar.getInstance();
        nowTime.add(calendarField, calendarInterval);
        Date expiresDate = nowTime.getTime();

        // header Map
        Map<String, Object> map = new HashMap<>();
        map.put("alg", "HS256");
        map.put("typ", "JWT");

        // build token
        // param backups {iss:Service, aud:APP}
        String token = JWT.create().withHeader(map) // header
                .withClaim("iss", "Service") // payload
                .withClaim("aud", "APP").withClaim("user_id", null == user_id ? null : user_id.toString())//可增加信息，如用户名或者用户的所有信息
                .withIssuedAt(iatDate) // sign time
                .withExpiresAt(expiresDate) // expire time
                .sign(Algorithm.HMAC256(SECRET)); // signature

        return token;
    }

    /**
     * 解密Token
     * 
     * @param token
     * @return
     * @throws Exception
     */
    public static Map<String, Claim> verifyToken(String token) {
        DecodedJWT jwt = null;
        try {
            JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).build();
            jwt = verifier.verify(token);
        } catch (Exception e) {
            // e.printStackTrace();
            // token 校验失败, 抛出Token验证非法异常
        }
        return jwt.getClaims();
    }

    /**
     * 根据Token获取user_id
     * 
     * @param token
     * @return user_id
     */
    public static Long getAppUID(String token) {
        Map<String, Claim> claims = verifyToken(token);
        Claim user_id_claim = claims.get("user_id");
        if (null == user_id_claim || StringUtils.isEmpty(user_id_claim.asString())) {
            // token 校验失败, 抛出Token验证非法异常
        }
        return Long.valueOf(user_id_claim.asString());
    }
    
    public static void main(String[] args){
        String token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJBUFAiLCJ1c2VyX2lkIjoiMTAiLCJpc3MiOiJTZXJ2aWNlIiwiZXhwIjoxNTQ2NTkyMjIyLCJpYXQiOjE1NDU3MjgyMjJ9.rITMUr9UU1nYi1vFiazIrc5JBCFldi7J6LWuVD6ctRs";
        Map<String, Claim> stringClaimMap = JwtUtil.verifyToken(token);
        Long appUID = JwtUtil.getAppUID(token);
        System.out.println(appUID);
        /*String token = null;
        try {
            token = createToken(2L);    
        }catch (Exception e){
            log.error("生成token失败");
        }
        System.out.println(token);
        log.info("解密token");
        Map<String, Claim> stringClaimMap = verifyToken(token);
        for (String s : stringClaimMap.keySet()) {
            log.info(s+"----------->"+stringClaimMap.get(s));
        }
        log.info("获取用户信息");
        Long appUID = getAppUID(token);
        System.out.println(appUID);*/
    }
}
